`pdfReplaceImage`

Swap out an already-inserted image's underlying pixel data

BOOL32 __stdcall pdfReplaceImageA(PPDF IPDF, TPDFImage* Source, const char* Image, uint32_t Index, TExtColorSpace CS, int32_t CSHandle, TReplaceImageFlags Flags);
BOOL32 __stdcall pdfReplaceImageW(PPDF IPDF, TPDFImage* Source, const wchar_t* Image, uint32_t Index, TExtColorSpace CS, int32_t CSHandle, TReplaceImageFlags Flags);
BOOL32 __stdcall pdfReplaceImageEx(PPDF IPDF, TPDFImage* Source, void* Buffer, uint32_t BufSize, uint32_t Index, TExtColorSpace CS, int32_t CSHandle, TReplaceImageFlags Flags);

Delphi

function pdfReplaceImageA(const IPDF: PPDF; Source: PPDFImage; const Image: PAnsiChar; Index: Cardinal; CS: TExtColorSpace; CSHandle: Integer; Flags: TReplaceImageFlags): LongBool; stdcall;
function pdfReplaceImageW(const IPDF: PPDF; Source: PPDFImage; const Image: PWideChar; Index: Cardinal; CS: TExtColorSpace; CSHandle: Integer; Flags: TReplaceImageFlags): LongBool; stdcall;
function pdfReplaceImageEx(const IPDF: PPDF; Source: PPDFImage; Buffer: Pointer; BufSize: Cardinal; Index: Cardinal; CS: TExtColorSpace; CSHandle: Integer; Flags: TReplaceImageFlags): LongBool; stdcall;

Purpose. Swap out an already-inserted image's underlying pixel data for a new file/buffer, while every page reference to it (via the shared XObject alias) picks up the new content automatically.

Description. Verified major parameter reduction: despite the ABI accepting Source (a TPDFImage* — presumably meant as an alternative, struct-based way to identify the target image, alongside or instead of Index), CS/CSHandle (presumably meant to force the replacement into a specific color space), and Flags (a TReplaceImageFlags set, presumably selecting resize/aspect/re-encode behavior), none of Source, CS, CSHandle, or Flags is passed through to the underlying ReplaceImageFileH/ReplaceImageBufH implementation — only Index (the target image's handle) and the new file path/buffer actually reach the replace logic. The real implementation (ApplyLoadedImage) simply overwrites the target FImages entry's decoded pixel data, dimensions, and format flags in place, keeping the same handle/alias — no color-space conversion, resizing, or any Flags-driven behavior occurs regardless of what is passed for those four parameters.

Parameters.

Parameter	Description
`IPDF`	Document handle.
`Source`	Accepted but never read.
`Image`/`Buffer`	New file path (`A`/`W`) or buffer bytes (`Ex`) to decode and substitute.
`Index`	The target image's existing handle — this is the only "which image" parameter actually honored.
`CS`, `CSHandle`	Accepted but never read — no color-space conversion occurs.
`Flags`	Accepted but never read — no flag-driven behavior occurs.

Return value. True if Index resolved to an existing image and the new file/buffer decoded successfully; False otherwise.

See also. pdfInsertImage.

C# (P/Invoke)

wrappers/dotnet/LumasPdf.cs

[return: MarshalAs(UnmanagedType.Bool)]

Area

Images